Information processing apparatus capable of selecting among a plurality of power saving modes using a simple operation, and control method and storage medium therefor

ABSTRACT

An information processing apparatus capable of changing a state of power supply to respective parts of the apparatus with less user operation. When a sleep recovery button is depressed in a power saving mode, a button depression time is measured, and whether a length of the measure depression time exceeds a threshold value is determined. If the depression time exceeds the threshold value, a normal power mode is selected as power mode after transition. If the depression time does not exceed the threshold value, another power saving mode is selected as power mode after transition. According to the selected power mode, a state of power supply to respective parts of the apparatus is changed.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an information processing apparatuscapable of reducing power consumption, and relates to a control methodand a storage medium therefor.

Description of the Related Art

In recent years, information processing apparatuses such asmulti-function peripherals, printers, and facsimile machines have beenconfigured to reduce power consumption. For example, there has beenproposed an image forming apparatus that controls power saving modes ofpower savable parts of the apparatus according to a function selectedfrom a plurality of functions of the apparatus (see, for example,Japanese Laid-open Patent Publication No. 2001-201986).

Japanese Laid-open Patent Publication No. 2010-064315 discloses an imageforming apparatus in which an extension time is added to a basic settingtime in response to an extension instruction button being pressed,whereby a mode setting time until a shift to a power saving mode (sleepmode) is newly determined to extend a time period until a shift is madefrom active mode to sleep mode (i.e., a time period during which theactive mode is retained).

However, in the image forming apparatus disclosed in Japanese Laid-openPatent Publication No. 2010-064315, a sleep mode release button ispressed to return from the sleep mode to the active mode, and theextension instruction button is pressed to extend the time period forwhich the active mode is retained. In other words, the operation forreturning from the sleep mode and the operation for extending the timeperiod for which the active mode is retained must be made separatelyfrom each other.

It should be noted that Japanese Laid-open Patent Publication No.2010-064315 does not suggest a construction that enables a return from apower saving mode to a power mode desired by the user with less useroperation in an apparatus having a plurality of power saving modes suchas one disclosed in Japanese Laid-open Patent Publication No.2001-201986.

SUMMARY OF THE INVENTION

The present invention provides an information processing apparatus and acontrol method and a storage medium therefor, with which a state ofpower supply to respective parts of the apparatus can be changed withless user operation.

According to one aspect of this invention, there is provided aninformation processing apparatus that has a plurality of power modesincluding a normal power mode and at least one power saving mode andthat performs a mode changeover among the plurality of power modes,thereby changing a state of power supply to respective parts of theapparatus, which comprises an operation unit configured to be operatedto make a transition from one of the at least one power saving mode toanother power mode, a measurement unit configured to measure anoperation time of the operation unit, a selection unit configured toselect a power mode after transition according to a length of theoperation time of the operation unit measured by the measurement unit,and a control unit configured to change the state of power supply torespective parts of the apparatus according to the power mode selectedby the selection unit.

With this invention, a power mode after transition is selected accordingto a length of operation time of the operation unit, which is operatedto make a transition from a power saving mode to another power modeamong power modes, and the state of power supply to respective parts ofthe apparatus is changed according to the selected power mode, wherebythe state of power supply to respective parts of the apparatus can bechanged with less user operation in a short period of time.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically showing the construction of animage forming apparatus, which is an example of an informationprocessing apparatus according to a first embodiment of this invention;

FIG. 2 is a view showing an example of a power supply management tablein which a correspondence relation between power modes of the imageforming apparatus and states of power supply to respective parts of theimage forming apparatus is shown;

FIG. 3 is a flowchart showing the flow of a power mode selection andtransition process executed when a sleep recovery button (a button forrecovery from sleep) is depressed;

FIG. 4 is a flowchart showing details of a depression time measurementprocess executed in step S302 of FIG. 3;

FIG. 5 is a flowchart showing details of a power mode selection processexecuted in step S303 of FIG. 3;

FIG. 6 is a flowchart showing details of a power mode transition processexecuted in step S304 of FIG. 3;

FIG. 7 is a time chart showing transitions of the state of power supplyto respective parts of the image forming apparatus observed when thesleep recovery button is depressed in a state that a CPU of the imageforming apparatus stops operating;

FIG. 8 is a flowchart showing the flow of a depression time measurementprocess executed in step S302 of the power mode selection and transitionprocess of FIG. 3 when the sleep recovery button is depressed in a statethat the CPU stops operating; and

FIG. 9 is a flowchart showing the flow of an auto sleep timer valuesetting process according to a second embodiment of this invention.

DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described in detail below withreference to the drawings showing preferred embodiments thereof.

First Embodiment

FIG. 1 schematically shows in block diagram the construction of an imageforming apparatus, which is an example of an information processingapparatus according to a first embodiment of this invention.

As shown in FIG. 1, the image forming apparatus 1 has a scanner unit 2that functions as a reading unit for optically reading an image from adocument. The scanner unit 2 includes a document feeder unit (DF unit)21 for automatically feeding documents one by one from a document bundleset on the DF unit, and a scanning unit 22 for optically scanning eachdocument to obtain a digital image.

A printer unit 4 prints out a digital image on a paper medium. Theprinter unit 4 includes a sheet feed unit 43 capable of feeding sheetsone by one from a sheet bundle set thereon, a marking unit 41 forprinting image data on a fed sheet, and a sheet discharge unit 42 fordischarging a printed sheet.

A controller 3 that has a CPU 31, a hard disk 32, and a memory 33controls transmission and reception of image data between the scannerunit 2 and the printer unit 4, and can store image data. Under thecontrol of the controller 3, image data received from the scanner unit 2is temporarily stored into the memory 33 and then stored into the harddisk 32, for example. The hard disk 32 can store digital image, controlprograms, etc. Under the control of the controller 3, image data istemporarily stored from the hard disk 32 into the memory 33 andtransmitted from the memory 33 to the printer unit 4, whereby the imagedata can be printed out.

An image processing unit 5 has a general-purpose image processor 51 bywhich image data stored in the memory 33 can be reduction-processed, forexample. The processed image data can be stored again into the memory33.

According to an instruction from the CPU 31, a FAX_I/F 7 transmits, viafacsimile, digital image through e.g. a telephone line 70, andexternally receives facsimile data through e.g. the telephone line 70.

An operation unit 8 has a display device for displaying image formingapparatus setting information and job information to a user. Theoperation unit 8 includes keys and buttons for operating the imageforming apparatus 1 such as, for example, a button 80 for recovery fromsleep (operation button), which will be referred to as the sleeprecovery button 80. The sleep recovery button 80 is operated to transitthe image forming apparatus 1 from a power saving state to a normalpower state or to another power saving state.

A LAN_I/F 9 controls communication with an external computer 90 via LAN.The CPU 31 can input and output a digital image from and to the computer90 via the LAN, can issue a job, and can give an instruction to adevice. The CPU 31 can interpret an instruction for operation given fromthe operation unit 8 and can interpret instruction information givenfrom the computer 90, whereby a variety of jobs can be carried out.

A power unit 6 has an AC-DC converter 60 connected to an external ACpower source 100 via a switch 10 that is provided in the image formingapparatus 1. The power unit 6 includes switches 61-64 interposed betweenthe AC-DC converter 60 and respective ones of the controller 3, printerunit 4, scanner unit 2, and image processing unit 5. When the switch 10is ON, power is supplied from the AC power source 100 to the AC-DCconverter 60 in which DC powers are generated. The DC powers aresupplied to respective parts of the image forming apparatus 1 via theswitches 61-64 that are on-off controlled by the CPU 31.

More specifically, the CPU 31 controls the on-off of the switch 61 toon-off control the supply of controller power PW3 from the AC-DCconverter 60 to the controller 3, controls the on-off of the switch 62to on-off control the supply of printer unit power PW4 from the AC-DCconverter 60 to the printer unit 4, and controls the on-off of theswitch 63 to on-off control the supply of scanner unit power PW2 fromthe AC-DC converter 60 to the scanner unit 2. The CPU 31 also controlsthe on-off of the switch 64 to on-off control the supply ofgeneral-purpose image processor power (hereinafter, referred to as theimage processor power) PW5 from the AC-DC converter 60 to the imageprocessing unit 5.

When the controller power PW3 is cut off, the CPU 31 of the controller 3is not supplied with power. Accordingly, the controller 3 has a sleeprecovery circuit 34 for turning on the controller power PW3.

The image forming apparatus 1 has a copy function, image transmissionfunction, image storage function, image printing function, FAX receptionprinting function, FAX transfer function, FAX memory reception function,and FAX transmission function.

The copy function is used to store an image read from the scanner unit 2into the hard disk 32 and to print the image by the printer unit 4. Theimage transmission function is used to store an image read from thescanner unit 2 into the hard disk 32 and to transmit the image to thecomputer 90 via the LAN. The image storage function is used to store animage read from the scanner unit 2 into the hard disk 32 and whererequired, to transmit or print the image. The image printing function isused to analyze PDL (page description language) data received from thecomputer 90 and to print the data by the printer unit 4.

The FAX reception printing function is used to store a FAX imagereceived from the FAX_I/F 7 into the hard disk 32 and to print the FAXimage by the printer unit 4. The FAX transfer function is used to storea FAX image received from the FAX_I/F 7 into the hard disk 32 and totransfer the FAX image to e.g. the computer 90 via the LAN. The FAXmemory reception function is used to store a FAX image received from theFAX_I/F 7 into the hard disk 32 and to wait for the FAX image beingreferred to by an operator (user). The FAX transmission function is usedto store an image read from the scanner unit 2 into the hard disk 32 andto transmit the image from the FAX_I/F 7 to the telephone line 70.

It should be noted that an image is stored into the hard disk 32 in manycases when the above-described functions are used. This is because toprepare for failure of job execution and to recover from an abnormalstate such as power disconnection.

The image forming apparatus 1 has a function to shift from a normalpower state to a power saving state where the controller power PW3 isturned off or to another power saving state where the controller powerPW3 is turned off, and has a function to return from the power savingstate to the other power saving state or to the normal power state.

In the sleep state, each of peripheral devices of the CPU 31 (such asthe hard disk 32, memory 33, image processing unit 5, scanner unit 2,printer unit 4, LAN_I/F 9, operation unit 8, and FAX_I/F 7) is in asuspend state (e.g., ACPI-S3 state). In other words, the power PW1 atthe time of sleep is supplied only to a job detection part of the imageforming apparatus 1. Therefore, the power consumption of the entireapparatus becomes extremely small. Before entering sleep, the CPU 31stores the state of the image forming apparatus 1 into the memory 33,and then turns off the supply of the controller power PW3 to thecontroller 3. As a result, the CPU 31 of the controller 3 does notoperate. However, since the power PW1 at the time of sleep is suppliedto respective ones of part of the FAX_I/F 7, part of the operation unit8, part of the LAN_I/F 9, the sleep recovery circuit 34, and the memory33, a return instruction can be detected, whereby the sleep state can betransferred to a standby state

When network reception is performed via the LAN_I/F 9, or when FAX callis received via the FAX_I/F 7, or when the sleep recovery button 80 ofthe operation unit 8 is pressed, the sleep recovery circuit 34 detects areturn signal, and turns on the switch 61 to thereby turn on the supplyof the controller power PW3.

The CPU 31 reads the apparatus state stored in the memory 33 therefrom,and performs resetting to make a shift to the state (e.g., standbystate) immediately before the supply of the controller power PW3 wasturned off.

In the standby state, the CPU 31 receives, e.g., a job input by anoperator via the operation unit 8 or a job transmitted from the computer90 via the LAN_I/F, and turns on the supply of power (among the printerunit power PW4, scanner unit power PW2, and image processor power PW5,which were turned off in the sleep state) to one or more devices usedfor job execution.

In the case of copy job, the supply of scanner unit power PW2 andprinter unit power PW4 is turned on. In the case of image transmissionjob or image storage job, only the supply of scanner unit power PW2 isturned on. In the case of image printing job, only the supply of printerunit power PW4 is turned on. In the case of FAX reception printing job,the supply of printer unit power PW4 and image processor power PW5 isturned on. In the case of FAX transfer job or FAX memory reception job,only the supply of image processor power PW5 is turned on. In the caseof FAX transmission job, the supply of scanner unit power PW2 and imageprocessor power PW5 is turned on.

When the standby state is resumed after completion of the job execution,the supply of power to the device(s) used for the job execution isstopped, thereby reducing standby power consumed in the standby state.

The image forming apparatus 1 has an auto sleep timer function ofautomatically shifting to the sleep state when the user does not operatethe operation unit 8 for a predetermined time period in the standbystate, so that no job is input within the predetermined time period. Anauto sleep timer value representing a time period until automaticallyshifted from the standby state to the sleep state by the auto sleeptimer function is set by the user through the operation unit 8 andstored into the hard disk 32, for example.

At startup of the image forming apparatus 1, the auto sleep timer valueread from the hard disk 32 is written into an auto sleep timer valuestorage area of the memory 33. A timer (not shown) provided in the CPU31 performs count-down from the auto sleep timer value (initial value).When the count value of the timer becomes zero, a timer interruptionoccurs and interruption is notified to software running on the CPU 31,and transition processing from standby state to sleep state is performedby the CPU 31. On the other hand, when a user operation is performedthrough the operation unit 8 or a job is input before the count value ofthe timer becomes zero (i.e., before lapse of the setting time period),the timer is set with the auto sleep timer value and then restarted.

FIG. 2 shows an example of a power supply management table in which acorrespondence relation between power modes of the image formingapparatus 1 and states of power supply to respective parts of the imageforming apparatus 1 is shown.

Referring to FIG. 2, the power supply management table 200 includes apower mode field 201, controller power state field 202, printer unitpower state field 203, scanner unit power state field 204, and imageprocessor power state field 205.

In the power mode field 201, there are shown six power modes, i.e., anormal power mode and first to fifth power saving modes. Each of thepower state fields 202 to 205 has six ON/OFF information fieldsrespectively corresponding to the six power modes. In each of the ON/OFFinformation fields, there is shown ON information representing thatpower is to be supplied to a corresponding device or OFF informationrepresenting that power is not to be supplied to the correspondingdevice.

The ON information is indicated in the ON/OFF information fields of thepower state fields 202 to 205 corresponding to the normal power mode.This indicates that the supply of controller power PW3, printer unitpower PW4, scanner unit power PW2, and image processor power PW5 isturned on in the normal power mode. In the normal power mode, the poweris supplied to all the devices used for execution of various jobs suchas copy job, whereby various jobs can be carried out immediately.

The ON information is indicated in the ON/OFF information fields of thepower state fields 202, 203 and 205 corresponding to the first powersaving mode, and the OFF information is indicated in the ON/OFFinformation field of the power state field 204 corresponding to thefirst power saving mode. This indicates that the supply of controllerpower PW3, printer unit power PW4, and image processor power PW5 isturned on and the supply of scanner unit power PW2 is turned off in thefirst power saving mode. The first power saving mode is used, forexample, when print data received from the LAN_I/F 9 is image-processedby the image processor 51 and the processed image is printed by theprinter unit 4.

The ON information is indicated in the ON/OFF information fields of thepower state fields 202, 204 and 205 corresponding to the second powersaving mode, and the OFF information is indicated in the ON/OFFinformation field of the power state field 203 corresponding to thesecond power saving mode. This indicates that the supply of controllerpower PW3, scanner unit power PW2, and image processor power PW5 isturned on and the supply of printer unit power PW4 is turned off in thesecond power saving mode. The second power saving mode is used, forexample, when image data read by the scanner unit 2 is image-processedby the general-purpose image processor 51 and the processed image istransmitted to the computer 90 via the LAN_I/F 9.

The ON information is indicated in the ON/OFF information fields of thepower state fields 202, 205 corresponding to the third power saving modeand the OFF information is indicated in the ON/OFF information fields ofthe power state fields 203, 204 corresponding to the third power savingmode. This indicates that the supply of controller power PW3 and imageprocessor power PW5 is turned on and the supply of scanner unit powerPW2 and printer unit power PW4 is turned off in the third power savingmode. The third power saving mode is used, for example, when image datareceived via the LAN_I/F 9 is image-processed by the general-purposeimage processor 51 and the processed image is stored into the hard disk32.

The ON information is indicated in the ON/OFF information field of thepower state field 202 corresponding to the fourth power saving mode, andthe OFF information is indicated in the ON/OFF information fields of thepower state fields 203 to 205 corresponding to the fourth power savingmode. This indicates that the supply of controller power PW3 is turnedon and the supply of printer unit power PW4, scanner unit power PW2, andimage processor power is turned off in the fourth power saving mode. Thefourth power saving mode is used, for example, when an inquiry about thestate of the image forming apparatus 1 is received from the computer 90via the LAN_I/F 9, and a response notifying the apparatus state istransmitted to the computer 90 via the LAN_I/F 9.

The OFF information is indicated in the ON/OFF information fields of thepower state fields 202 to 205 corresponding to the fifth power savingmode. This indicates that the supply of controller power PW3, scannerunit power PW2, image processor power PW5, and printer unit power PW4 isturned off in the fifth power saving mode. In the fifth power savingmode, none of the devices is supplied with power. Among the six powermodes, the fifth power saving mode is the lowest in power consumptionand highest in power saving effect.

Next, a description will be given of a power mode selection andtransition process that is executed according to a length of depressiontime of the sleep recovery button 80. In this process, a power modeafter transition is selected and a transition to the selected power modeis performed.

FIG. 3 shows in flowchart the flow of a power mode selection andtransition process executed when the sleep recovery button 80 isdepressed in a case where current power mode is one of the first tofourth power saving modes shown in FIG. 2 (i.e., in a state that the CPU31 is supplied with power). It should be noted that the power modeselection and transition process of FIG. 3 and processes described laterare each performed by the CPU 31 by executing a relevant control programread from the hard disk 32 or the like.

In step S301, the CPU 31 determines whether or not the sleep recoverybutton 80 is depressed. More specifically, when the sleep recoverybutton 80 is depressed, an interruption signal is input via theoperation unit 8 to the CPU 31, thereby notifying the interruption tosoftware running on the CPU 31. In other words, when the interruption isnotified, it is determined that the sleep recovery button 80 isdepressed.

If the sleep recovery button 80 is not depressed (NO to step S301), theprocess returns to step S301. On the other hand, if the sleep recoverybutton 80 is depressed (YES to step S301), the CPU 31 performs adepression time measurement process, thereby measuring a depression timeof the sleep recovery button 80 (step S302). The details of thedepression time measurement process will be described later withreference to FIG. 4.

In step S303, the CPU 31 performs a power mode selection process basedon the button depression time measured in step S302, thereby selecting apower mode after transition. The details of the power mode selectionprocess will be described later with reference to FIG. 5.

In step S304, the CPU 31 confirms the power supply destination in thepower mode after transition selected in step S303, while referring tothe power supply management table 200 of FIG. 2, and performs a powermode transition process (details of which will be described later withreference to FIG. 6) for transition to the power mode after transition.Then, the present process is completed.

FIG. 4 shows in flowchart the details of the depression time measurementprocess executed in step S302 of FIG. 3.

First, the CPU 31 stores, as a depression start time Ts, a time point atwhich the sleep recovery button 80 is pressed (step S401). Morespecifically, the CPU 31 has a timer register that counts a clock pulsesupplied thereto, and the OS running on the CPU 31 performs timemanagement based on register value. When the sleep recovery button 80 ispressed and an interruption signal is supplied to the CPU 31, thesoftware running on the CPU 31 obtains the depression start time Ts viathe OS and stores the depression start time Ts into the memory 33.

Next, in step S402, the CPU 31 determines whether or not an interruptionrelease signal is input, thereby determining whether the press of thesleep recovery button 80 is released. If the press of the button 80 isnot released (NO to step S402), the process returns to step S402. On theother hand, the press of the button 80 is released (YES to step S402),the CPU 31 stores, into the memory 33, a time point where the press ofthe sleep recovery button 80 is released, as a depression end time Te(step S403).

Next, the CPU 31 reads the depression start time Ts and the depressionend time Te stored in the memory 33, and calculates a button depressiontime Ti by subtracting the depression start time Ts from the depressionend time Te (step S404).

Next, the CPU 31 stores the button depression time Ti calculated in stepS404 into the memory 33 (step S405), and returns to the power modeselection and transition process of FIG. 3.

FIG. 5 shows in flowchart the details of the power mode selectionprocess executed in step S303 of FIG. 3 based on the button depressiontime Ti obtained in the depression time measurement process of FIG. 4.

At start of the power mode selection process, the CPU 31 compares thebutton depression time Ti read from the memory 33 with a threshold valueTlm read from the hard disk 32, thereby determining whether or not thebutton depression time Ti exceeds the threshold value Tlm (step S501).If the button depression time Ti exceeds the threshold value Tlm (YES tostep S501), the CPU 31 selects a first particular power mode (e.g.,normal power mode), which is set in advance by the user as a power modeafter transition at the time of long press (step S502).

On the other hand, if the button depression time Ti does not exceed thethreshold value Tlm (NO to step S501), the CPU 31 selects a secondparticular power mode (e.g., second power saving mode), which is set inadvance by the user as a power mode after transition at the time ofshort press (step S503).

On the screen of the operation unit 8, the user can set and change thepower modes after transition at the time of long press and at the timeof short press of the sleep recovery button 80. The set power modesafter transition are stored into the hard disk 32.

In step S504, the CPU 31 stores, into the memory 33, the power modeSmode after transition selected in step S502 or in step S503, andreturns to the power mode selection and transition process of FIG. 3.

FIG. 6 shows in flowchart the details of the power mode transitionprocess executed in step S304 of FIG. 3 based on the power mode aftertransition selected in the power mode selection process of FIG. 5.

In step S601, the CPU 31 reads from the memory 33 the current power modestored in the memory 33 and the power mode Smode after transition storedinto the memory 33 in step S504 of FIG. 5. Information representing thecurrent power mode is updated and overwritten to the memory 33 each timethe power mode is changed. As previously described, the current powermode in this example is one of the first to fourth power saving modesshown in FIG. 2 and will be referred to as the current power saving modeSnow.

In step S602, while referring to the power supply management table 200of FIG. 2, the CPU 31 determines whether or not OFF information isindicated in the ON/OFF information field of the printer unit powerstate field 203 corresponding to the current power saving mode and ONinformation is indicated in the ON/OFF information field of the printerunit power state field 203 corresponding to the power mode aftertransition. In other words, the CPU 31 determines whether or not thesupply of printer unit power PW4 is turned off in the current powersaving mode and is to be turned on in the power mode after transition(step S602).

If the answer to step S602 is YES, i.e., if the supply of printer unitpower PW4 is to be switched from OFF to ON, the CPU 31 controls theswitch 62 to turn on the supply of printer unit power PW4 (step S603),and proceeds to step S606. On the other hand, if the answer to step S602is NO, the CPU 31 determines whether or not the supply of printer unitpower PW4 is turned on in the current power saving mode and is to beturned off in the power mode after transition (step S604).

If the answer to step S604 is YES, the CPU 31 controls the switch 62 toturn off the supply of printer unit power PW4 (step S605). On the otherhand, if the answer to step S604 is NO, the process proceeds to stepS606.

In step S606, the CPU 31 determines whether or not the supply of scannerunit power PW2 is turned off in the current power saving mode and is tobe turned on in the power mode after transition. If the answer to stepS606 is YES, the CPU 31 controls the switch 63 to turn on the supply ofscanner unit power PW2 (step S607), and proceeds to step S610. On theother hand, if the answer to step S606 is NO, the CPU 31 determineswhether or not the supply of scanner unit power PW2 is turned on in thecurrent power saving mode and is to be turned off in the power modeafter transition (step S608). If the answer to step S608 is YES, the CPU31 controls the switch 63 to turn off the supply of scanner unit powerPW2 (step S609). On the other hand, if the answer to step S608 is NO,the process proceeds to step S610.

In step S610, the CPU 31 determines whether or not the supply of imageprocessor power PW5 is turned off in the current power saving mode andis to be turned on in the power mode after transition. If the answer tostep S610 is YES, the CPU 31 controls the switch 64 to turn on thesupply of image processor power PW5 (step S611), and returns to thepower mode selection and transition process of FIG. 3. On the otherhand, if the answer to step S610 is NO, the CPU 31 determines whether ornot the supply of image processor power PW5 is turned on in the currentpower saving mode and is to be turned off in the power mode aftertransition (step S612). If the answer to step S612 is YES, the CPU 31controls the switch 64 to turn off the supply of image processor powerPW5 (step S613), and returns to the power mode selection and transitionprocess of FIG. 3. On the other hand, if the answer to step S612 is NO,the process returns to the process of FIG. 3.

As described above, the state of power supply to respective parts of theimage forming apparatus is switched according to the power mode aftertransition, and the power mode transition process is executed. Aftercompletion of the power mode transition process, the current powersaving mode Snow is updated to the power mode Smode after transition,and the updated mode is overwritten and stored into the memory 33.

FIG. 7 shows, in time chart, transitions of the state of power supply torespective parts of the image forming apparatus 1 observed when thepower mode is the fifth power saving mode shown in FIG. 2 and when thesleep recovery button 80 is depressed in a state that the CPU 31 stopsoperating.

In FIG. 7, an ON/OFF change of the sleep recovery button 80, an ON/OFFchange of operation of the CPU 31, ON/OFF changes of supply ofcontroller power PW3, scanner unit power PW2, and image processor powerPW5, and a power mode change are shown with the lapse of time.

If the power mode before the sleep recovery button 80 is pressed is thefifth power saving mode as shown in FIG. 7, the supply of controllerpower PW3, scanner unit power PW2, and image processor power PW5 isturned off, and the CPU 31 stops operating.

When the depression of the sleep recovery button 80 is started at a timepoint of Ts, the sleep recovery button 80 changes from OFF to ON.Subsequently, the sleep recovery circuit 34 operates, the supply ofcontroller power PW3 is started, and the power mode is transited fromthe fifth power saving mode to the fourth power saving mode.

When the supply of controller power PW3 is stabilized at a time point ofTc, the CPU 31 is reset-released and restarts the operation.

When the completion of depression of the sleep recovery button 80 isdetected at the time point of Te, the button depression time iscalculated and based on the calculated time, a power mode aftertransition is selected. In this example, the second power saving mode isselected as the power mode after transition, and a transition processfrom the fourth power saving mode to the second power saving mode isperformed. In the transition process to the second power saving mode,the supply of scanner unit power PW2 and image processor power PW5 isrestarted, and the transition to the second power saving mode iscompleted.

As shown in FIG. 7, the button depression time Ti is represented by thesum of a time period (hereinafter, referred to as the CPU restart waittime period) Tr from the start of button depression to the restart ofCPU operation and a time period from the CPU operation restart time Tcto the button depression completion time Te.

During the CPU restart wait time period Tr, the CPU 31 stops operatingand cannot measure the CPU restart wait time period Tr. On the otherhand, the CPU restart wait time period Tr is determined by a processingtime period of the sleep recovery circuit 34 and a reset release waittime period, and therefore has nearly a constant value. At startup ofthe apparatus, a fixed value, which represents the CPU restart wait timeperiod Tr and which was stored into the hard disk 32 at fabrication ofthe image forming apparatus 1, is read from the hard disk 32 and storedinto the memory 33, whereby the CPU restart wait time period Tr can beread from the memory 33 when the button depression time is calculated.The button depression time Ti can be obtained by adding the CPU restartwait time period Tr to a time period measured by the CPU 31 from the CPUoperation restart time Tc to the button depression completion time Te.

In the following, a description will be given of the depression timemeasurement process executed when the sleep recovery button 80 ispressed in a case that the current power mode is the fifth power savingmode shown in FIG. 2, i.e., in a state that the CPU 31 stops operating.

FIG. 8 shows in flowchart the flow of the depression time measurementprocess executed in step S302 of the power mode selection and transitionprocess of FIG. 3 when the sleep recovery button 80 is pressed in astate that the CPU 31 stops operating.

When the sleep recovery button 80 is started to be depressed, the sleeprecovery circuit 34 operates, the switch 61 is turned on by the sleeprecovery circuit 34, and the supply of controller power PW3 is started(step S801). Until the voltage of controller power PW3 is stabilized,the CPU 31 is retained in a reset state for a predetermined time periodby a reset circuit (not shown). After the voltage is stabilized, the CPU31 is reset-released and restarts the operation (step S802).

Immediately after the operation is restarted, the CPU 31 obtains andstores the CPU operation start time Tc into the memory 33 (step S803),and detects by interruption whether or not the depression of the sleeprecovery button 80 is released (step S804). If the depression of thesleep recovery button 80 is not released, the process returns to stepS804. If the depression of the sleep recovery button 80 is released, theCPU 31 obtains the depression end time Te at which the depression of thesleep recovery button 80 is ended, and stores the obtained time Te intothe memory 33 (step S805).

Next, the CPU 31 reads from the memory 33 and obtains the CPU restartwait time period Tr, CPU operation start time Tc, and depression endtime Te (step S806). Then, the CPU 31 calculates a time period from theCPU operation start time Tc to the depression end time Te, and adds theCPU restart wait time period Tr to the calculated time period to therebycalculate a button depression time Ti (step S807). The CPU 31 stores thecalculated button depression time Ti into the memory 33 (step S808), andreturns to the power mode selection and transition process of FIG. 3.

With the depression time measurement process described above, thedepression time of the sleep recovery button 80 can correctly bedetermined, even if the power mode is transited from a state where theCPU 31 stops operating.

According to the first embodiment, one of the power modes set in advanceby the user is selected according to a length of depression time of thesleep recovery button 80, and the state of supply of power to respectiveparts of the image forming apparatus is changed based on the selectedpower mode, whereby a transition to the power mode set by the user canbe achieved with less user operation in a short time.

Second Embodiment

An image forming apparatus according to a second embodiment of thisinvention is basically the same as that of the first embodiment exceptthat the auto sleep timer value is changed based on the buttondepression time of the sleep recovery button 80. A description of pointscommon to the first and second embodiments will be omitted.

FIG. 9 shows in flowchart the flow of an auto sleep timer value settingprocess of this embodiment. It should be noted that this process isexecuted by the CPU 31 by executing a relevant control program read frome.g. the hard disk 32 immediately after the power mode selection processof FIG. 5 or immediately after the power mode transition process of FIG.6, for example.

As with the case of the power mode selection process of FIGS. 3 and 5,the CPU 31 compares the button depression time Ti read from the memory33 with the threshold value Tlm read from the hard disk 32, anddetermines whether or not the button depression time Ti exceeds thethreshold value Tlm (step S901).

If the button depression time Ti exceeds the threshold value Tlm (YES tostep S901), the CPU 31 determines that the sleep recovery button 80 islong pressed, and calculates an extended auto sleep timer value Tas(step S902). The extended auto sleep timer value Tas can be calculatedby multiplying a default time value Tad (which is an ordinary auto sleeptimer value) by an extension magnification that is obtained by dividingthe button depression time Ti by the threshold value Tlm.

Next, the CPU 31 writes the extended auto sleep timer value Tas into anauto sleep timer value storage area of the memory 33 (step S903).

On the other hand, if the button depression time Ti does not exceed thethreshold value Tlm (NO to step S901), the CPU 31 writes the defaulttimer value Tad into the auto sleep timer value storage area of thememory 33 (step S904).

As described above, the selection of the power mode after transition andthe extension of the auto sleep timer value can be performed by a singlebutton depression operation.

According to the second embodiment, the auto sleep timer value isextended according to the length of depression time of the sleeprecovery button 80 in the image forming apparatus having the auto sleepfunction for making a transition to the sleep state when a predeterminedtime period corresponding to the auto sleep timer value has lapsed in apredetermined condition. This makes it possible, with less useroperation, to achieve a transition to the power mode set by the user andto extend the time period until the transition to the power mode isstarted.

In the auto sleep timer value setting process of FIG. 9, when the sleeprecovery button 80 is long pressed, the auto sleep timer value is alwaysextended. However, it is possible to allow the user to select whether ornot the timer value is to be extended in such a case. Although in theprocess of FIG. 9 the length of depression time of the sleep recoverybutton 80 is compared with one threshold value and the power mode aftertransition is selected from two candidate modes, two or more thresholdvalues can be used and the power mode after transition can be selectedfrom three or more candidate modes.

The information processing apparatus is configured by the image formingapparatus in the first and second embodiments, but can be configured byan apparatus other than the image forming apparatus, such as a portableinformation terminal, a PC, a cellular phone, or the like.

Other Embodiments

Embodiments of the present invention can also be realized by a computerof a system or apparatus that reads out and executes computer executableinstructions recorded on a storage medium (e.g., non-transitorycomputer-readable storage medium) to perform the functions of one ormore of the above-described embodiment (s) of the present invention, andby a method performed by the computer of the system or apparatus by, forexample, reading out and executing the computer executable instructionsfrom the storage medium to perform the functions of one or more of theabove-described embodiment (s). The computer may comprise one or more ofa central processing unit (CPU), micro processing unit (MPU), or othercircuitry, and may include a network of separate computers or separatecomputer processors. The computer executable instructions may beprovided to the computer, for example, from a network or the storagemedium. The storage medium may include, for example, one or more of ahard disk, a random-access memory (RAM), a read only memory (ROM), astorage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2013-138802, filed Jul. 2, 2013, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An information processing apparatus comprising: aload; an operation device having a display device and a buttonconfigured to be depressed to receive a user operation to return theinformation processing apparatus from a power saving state; and acontroller configured to shift the information processing apparatus tothe power saving state in which the display device is off and power tothe load is not supplied, wherein, in response to a depressing of thebutton, the controller is configured to: in a case where a depressiontime of the button is a predetermined value or more, shift theinformation processing apparatus from the power saving state to a firstpower state in which the display device is on and the power to the loadis supplied and, in a case where the depression time of the button isless than the predetermined value, shift the information processingapparatus from the power saving state to a second power state in whichthe display device is on and the power to the load is not supplied; in acase where the controller shifts the information processing apparatus tothe first power state, set a first time period based on the depressiontime of the button as a sleep shift time period required to shift theinformation processing apparatus to the power saving state from thefirst power state; and in a case where the controller shifts theinformation processing apparatus to the second power state, set apredefined second time period, which is shorter than the first timeperiod, as the sleep shift time period required to shift the informationprocessing apparatus to the power saving state from the second powerstate.
 2. The information processing apparatus according to claim 1,wherein the controller is further configured to calculate the depressiontime of the button.
 3. The information processing apparatus according toclaim 2, wherein the controller is further configured to calculate thedepression time of the button by using a start time of a buttondepression and an end time of the button depression.
 4. The informationprocessing apparatus according to claim 2, wherein the controllerincludes a processor, to which power is not supplied in the power savingstate, and wherein the processor is configured to start operation inresponse to a start of a button depression, and calculate the depressiontime of the button by using a start time of the operation and an endtime of the button depression.
 5. The information processing apparatusaccording to claim 1, wherein the load is a printer device that printsan image on a sheet.
 6. The information processing apparatus accordingto claim 1, wherein the load is a scanner device that reads an imageformed on an original.
 7. An information processing apparatuscomprising: a load; an operation device having a display device and abutton configured to be depressed to receive a user operation to returnthe information processing apparatus from a power saving state; and acontroller configured to shift the information processing apparatus tothe power saving state in which the display device is off and power tothe load is not supplied, wherein, in response to a depressing of thebutton, the controller is configured to in a case where a depressiontime of the button is a predetermined value or more, shift theinformation processing apparatus from the power saving state to a firstpower state in which the display, device is on and the power to the loadis supplied, and, in a case where the depression time of the button isless than the predetermined value, shift the information processingapparatus from the power saving state to a second power state in whichthe display device is on and the power to the load is not supplied, andwherein the controller is configured to shift the information processingapparatus to the power saving state from the first power state at a timewhen a first sleep shift time period based on the depression time of thebutton elapses after the information processing apparatus was shifted tothe first power state in response to the depressing of the button, andshift the information processing apparatus to the power saving statefrom the second power state at a time when a predefined second sleepshift time period, which is shorter than the first sleep shift timeperiod, elapses after the information processing apparatus was shiftedto the second power state in response to the depressing of the button.8. The information processing apparatus according to claim 7, whereinthe controller is further configured to calculate the depression time ofthe button.
 9. The information processing apparatus according to claim8, wherein the controller is further configured to calculate thedepression time of the button by using a start time of a buttondepression and an end time of the button depression.
 10. The informationprocessing apparatus according to claim 8, wherein the controllerincludes a processor, to which power is not supplied in the power savingstate, and wherein the processor is configured to start operation inresponse to a start of a button depression, and calculate the depressiontime of the button by using a start time of the operation and an endtime of the button depression.
 11. The information processing apparatusaccording to claim 7, wherein the load is a printer device that printsan image on a sheet.
 12. The information processing apparatus accordingto claim 7, wherein the load is a scanner device that reads an imageformed on an original.
 13. A control method for an informationprocessing apparatus that comprises a bad and an operation device havinga display device and a button configured to be depressed to receive auser operation to return the information processing apparatus from apower saving state, the method comprising: shifting the informationprocessing apparatus to the power saving state in which the displaydevice is off and power to the load is not supplied; in response to adepressing of the button, shifting, in a case where a depression time ofthe button is a predetermined value or more, the information processingapparatus from the power saving state to a first power state in whichthe display device is on and the power to the bad is supplied and,shifting, in a ease where the depression time of the button is less thanthe predetermined value, the information processing apparatus from thepower saving state to a second power state in which the display deviceis on and the power to the load is not supplied; in a case where theinformation processing apparatus is shifted to the first power state,setting a first time period based on the depression time of the buttonas a sleep shift time period required to shift the informationprocessing apparatus to the power saving state from the first powerstate; and in a case where the information processing apparatus isshifted to the second power state, setting a predefined second timeperiod, which is shorter than the first time period, as the sleep shifttime period required to shift the information processing apparatus tothe power saving state from the second power state.
 14. A control methodfor an information processing apparatus that comprises a bad and anoperation device having a display device and a button configured to bedepressed to receive a user operation to return the informationprocessing apparatus from a power saving state, the method comprising:shifting the information processing apparatus to the power saving statein which the display device is off and power to the bad is not supplied;in response to a depressing of the button, shifting, in a case where adepression time of the button is a predetermined value or more, theinformation processing apparatus from the power saving state to a firstpower state in which the display device is on and the power to the badis supplied and, shifting, in a case where the depression time of thebutton is less than the predetermined value, the information processingapparatus from the power saving state to a second power state in whichthe display device is on and the power to the load is not supplied;shifting the information processing apparatus to the power saving statefrom the first power state at a time when a first sleep shift timeperiod based on the depression time of the button elapses after theinformation processing apparatus was shifted to the first power state inresponse to the depressing of the button; and shifting the informationprocessing apparatus to the power saving state from the second powerstate at a time when a predefined second sleep shift time period, whichis shorter than the first sleep shift time period, elapses after theinformation processing apparatus was shifted to the second power statein response to the depressing of the button.